1. Field of the Invention
The present invention relates to a mixing-kneading extruder apparatus, and more particularly to a mixing-kneading extruder apparatus for mixing and kneading soap chips as raw material of soap or chemical materials such as various kinds of fat and oil and extruding the mixture into a predetermined shape.
2. Description of the Related Art
In a manufacturing process of e.g. soap, the temperature of the raw materials significantly affects workability and quality of the final product. In particular, it is important in the manufacture that the heat generated due to friction associated with compression and mixing/kneading of the raw soap material (material to be processed) in the course of the mixing/kneading and extruding process be adjusted so as to maintain the processed material at an appropriate temperature.
In the conventional mixing-kneading extruder apparatus of the above-noted type, a water passage is coaxially provided in an outer periphery of a cylinder incorporating therein a plodder worm shaft. In operation, by causing cooling water to flow through the water passage, heat exchange takes place between the processed material kneaded and extruded by the plodder worm shaft and an inner peripheral surface of the cooled cylinder, thereby to control the temperature of the processed material.
With the above arrangement, the conveying or plodding operation of the material by the plodder worm shaft may be effected efficiently, with avoiding co-rotation between this worm shaft and the material.
However, the temperature elevation in the processed material tends to take place at a levigating mechanism of the apparatus at which the material is subjected to a levigation treatment. And, with the above-described arrangement, there is a limit in positively controlling the temperature of the processed material at such area.
Further, with the conventional construction, the cooling is effected for only the outer periphery of the cylinder. Thus, the plodded material may be cooled only at the portion of thereof directly contacting with the inner periphery of the cylinder (i.e. the outer peripheral portion of the material), while the remaining portion of the material located adjacent the plodder worm shaft remains un-cooled directly, so that the temperature tends to rise at this portion.
That is to say, when the material is viewed along the cross section of the cylinder, the outer material portion adjacent the inner peripheral surface of the cylinder may be maintained at a relatively low temperature, while the inner portion thereof adjacent the plodder worm shaft tends to experience temperature rise. Accordingly, the temperature of the processed material varies in the radial direction of the cylinder, whereby quality irregularity occurs in the final product made from this material.
Depending on the kind of soap, it is not sufficient just to restrict the rise in the material temperature. It is further necessary to manufacture the product while maintaining the soap material, i.e. the processed material, at a predetermined elevated temperature such as 40.degree. to 45.degree. C. higher than the normal temperature. In such case, contrary to the above-described case, it becomes necessary to maintain the processed material at a predetermined elevated temperature. For this purpose, instead of the cooling water, heating water is used for maintaining the material at the predetermined elevated temperature. Like the foregoing case, in this case too, while the temperature of the portion of the material adjacent the inner peripheral surface of the cylinder may be relatively well controlled, it is difficult to effectively control the temperature of the remaining material portion located adjacent the plodder worm shaft.
The present invention attends to the above-described shortcomings of the prior art and its primary object is to provide an improved mixing-kneading extruder apparatus capable of effectively controlling the temperature of processed material such as raw soap material in the vicinity of a levigating mechanism thereof when the material is to to be processed at a predetermined temperature within a cylinder, minimizing irregularity in the temperature of the material in the radial direction of the cylinder, and providing a final product with uniform quality.